Production of staple fiber



July 15, 1941. E. A. MORTON ET AL 2,249,664

' PRODUCTION OF STAPLE FIBER Filed Dec. 11, 1940 2 Sheets-Sheet 2 INVENTORS ERIC ANDREW MORTON HAROLD ASHTON AND WILUAM HARDACRE by 71/: dr er/rays Patented July 15, 1941 2,249,664 PRODUCTION OF STAPLE FIBER Eric Andrew Morton, Coventry, Harold Ashton,

Slattocks, Itochdale, and Bradley, near Keighley,

in England, allignors to Courtaulds Limited, London, England, a

British company Application December 11, 1940, Serial No. 369,058

In Great 1 Claim.

This invention relates to the manufacture and production of staple fiber from a band, rope,

bundle or tow, hereinafter referred to as a tow, of continuous threads, filaments or the like obtained from viscose.

According to the present invention a tow of continuous filaments is converted into an even, coherent and draftable sliver of cut filaments of equal length by passing the tow of continuous filaments between the cylindrical surfaces of two hardened, non-resilient, rigidly mounted rollers, the distance between the said surfaces ofthe rollers in the nip being only a small fraction of the thickness of the loose tow of filaments so that the tow is highly compressed and gripped over an appreciable length in the nip, confining the compressed tow within a limited space in I the nip by means of guides and progressing the tow between the rollers by rotating them at substantially equal peripheral speeds, whereupon the continuous filaments are cut into equal lengths by helical cutting ridges arranged on one of the rollers at an angle of from to 1'5 to a plane perpendicular to the axis of the roller and of such depth that they touch the surface of the other roller in the nip.

Each ridge is V-shaped, the tip of the V being ground so as to form a flat surface. The ridges are preferably provided on the upper roller. The filaments are cut into lengths equal to the distance between adjacent ridges measured round the circumference of the roller. The rollers are made of hardened steel and driven by suitable gearing.

Guides are provided for confining the compressed tow within a limited space in the nip between the two rollers. If a number of tows.

are passed side by side through the same pair of cutting rollers, two such guides are used one at each end of the nip at the outer side of the two outermost tows. ,In addition further guides are provided to confine each tow separately, the said confining guides taking the form of circumferential ridges on one of the rollers. Each ridge is made of such dimensions that it fits closel into a corresponding slot in the other roller. In addition to such ridges and slots other guiding members, such as a row of pegs or a perforated bar, will be necessary immediatelybefore the nip of the cutting rollers for guiding the tow or tows in such a manner that their constituent filaments are not nipped between the aforesaid ridges and slots. Before reaching the cutting ridges the tow may be passed between other pairs of rollers or under or over single rollers in order Britain January 3, 194

to give it any desired tension or thickness or to assist in gripping the tow firmly while cutting is taking place.

Each tow'of continuous filaments is highly compressed and confined between the two rollers and the guiding members at the moment of bein cut and this coupled with the angle of the helical cutting ridges prevents the tow and single filaments thereof from being pushed sideways by the sides of the cutting ridges and enables a draftable sliver of cut filaments of equal length to be obtained.

The accompanying diagrammatic drawings illustrate one arrangement of apparatus suitable for carrying out the present invention.

Figure 1 is a side view in section of the apparatus.

Figure 2, an end view showing the arrangement of the cutting rollers, and 1 Figure 3 is a similar view showing confining guides and corresponding slots on the rollers.

A tow of continuous filaments l, for example of about 200,000 denier, is led through a guide 2 and tension rollers 3 to a pair of hard steel rollers 4 and 5, mounted on axles 6 and I respectively in a frame work 8. The upper roller 4 is provided with a numberof parallel helical ridges 9 which touch the smooth surface .of the lower roller 5 in the nip between the rollers. The ridges are of such depth that the distance between the cylindrical surfaces of the two rollers is about 0.06 of an inch, whereas the diameter of the tow i as it is delivered under tension is about 0.37 of an inch. The said ridges are V-shaped in section and slightly flattened at the tip and lie at an angle of 10 to a plane perpendicular tothe axis of the roller 4. The rollers are driven at substantiallyequal peripheral speeds in opposite directions by gear wheels IS. The rollers I are driven at a peripheral speed 'less than that of the rollers 4 and I, so that the tow I is under tension between the rollers '3 and the cutting rollers. The arrangement shown in Figure 3 is capable of cutting six separate tows. The lower roller 5 is provided with seven parallel circumferential ridges II which fit into corresponding circumferential slots I on the other roller 4. Immediately before the nip of the cutting rollers l and 5,- a guiding member is placed consisting of a row of pegs i'l. Each tow is passed through the space between two pegs. Each of the said spaces is narrower than the distance between adjacent ridges ll, so that none of the filaments of the tows is allowed to enter the slots it. As each tow is prograssed through the nip it completely fills the box-like space surrounded by the cylindrical surfaces 4 and 5 and the ridges it on both sides of it, so that cutting of all the filaments is ensured. The tow of staple fiber ii is much flatter as it leaves the nip between the rollers 4 and 5 than the tow of continuous filaments i. It is removed from the lower roller 5 by means of a tunnel i2 provided with an acute angled edge l3 fitted against the roller 5. From this funnel l2 the tow is led away by means of a conveyor belt Hi to further treatment.

What we claim is:

Apparatus for the production of an even, coherent and draftable sliver of cut filaments of equal length which comprises two hardened, nonresilient rigidly mounted rollers one of which has a smooth surface and the other a number of helical V-shaped cutting ridges arranged at an angle of between 5 and 15 to a plane perpendicular to the axis of the roller, the two rollers being so disposed that the said ridges touch the surface of the other roller in the nip and circumferential ridges on one roller fitting into corresponding circumferential slots on the other roller and means for guiding each tow within the limited space in the nip between adjacent circumferential ridges.

ERIC ANDREW MORTON. HAROLD ASHTON. WILLIAM HARDACRE. 

